U.S. patent application number 11/437763 was filed with the patent office on 2007-11-22 for radiopaque compositions, articles and methods of making and using same.
Invention is credited to Michael L. Bailey, James E. Swett.
Application Number | 20070270691 11/437763 |
Document ID | / |
Family ID | 38461109 |
Filed Date | 2007-11-22 |
United States Patent
Application |
20070270691 |
Kind Code |
A1 |
Bailey; Michael L. ; et
al. |
November 22, 2007 |
Radiopaque compositions, articles and methods of making and using
same
Abstract
A radiopaque composition and implant comprising a mixture of a
polymer, such as polyetherketone (PEEK), polyetherketone (PEK),
polyetherketoneketone (PEKK), polyetherimide, or polyphenylsulfone,
and bismuth trioxide (BiO.sub.3) is provided. The mixture comprises
BiO.sub.3 of about twenty to thirty percent (20% to 30%) by weight.
The composition is useful in radiopaque implants for mammals
including humans, such as in catheters, stents, screws, anchors,
dental caps and posts, bone and joint replacements, and the like.
The composition is also useful for radiopaque markers in implants
and for radiopaque articles used in surgical and other in vivo
procedures. The radiopaque items can be easily identified and
located in a patient's body via X-ray examination or
fluoroscopy.
Inventors: |
Bailey; Michael L.; (Oak
Harbor, WA) ; Swett; James E.; (Oak Harbor,
WA) |
Correspondence
Address: |
VINSON & ELKINS L.L.P.
1001 FANNIN STREET, 2300 FIRST CITY TOWER
HOUSTON
TX
77002-6760
US
|
Family ID: |
38461109 |
Appl. No.: |
11/437763 |
Filed: |
May 19, 2006 |
Current U.S.
Class: |
600/431 ;
623/1.34 |
Current CPC
Class: |
A61L 31/028 20130101;
A61L 27/18 20130101; A61L 31/06 20130101; A61L 27/025 20130101;
C08L 71/00 20130101; A61C 2201/005 20130101; A61L 29/18 20130101;
A61L 31/18 20130101; A61L 29/06 20130101; A61L 27/50 20130101; A61L
29/06 20130101; A61L 31/06 20130101; A61B 6/508 20130101; A61L
17/04 20130101; A61L 27/18 20130101; C08L 71/00 20130101; C08L
71/00 20130101; C08L 71/00 20130101 |
Class at
Publication: |
600/431 ;
623/1.34 |
International
Class: |
A61B 6/12 20060101
A61B006/12; A61F 2/02 20060101 A61F002/02 |
Claims
1. An implant for a mammal comprising an object comprising
polyetheretherketone (PEEK) and at least ten percent (10%) by
weight bismuth trioxide (BiO.sub.3).
2. The implant according to claim 1 wherein the mammal comprises a
human being.
3. The implant according to claim 1 wherein the implant further
comprises at least about twenty percent (20%) by weight
BiO.sub.3.
4. The implant according to claim 1 wherein the implant further
comprises about thirty percent (30%) by weight BiO.sub.3.
5. The implant according to claim 3 wherein said implant comprises
a spinal cage.
6. The implant according to claim 4 wherein said implant comprises
a spinal cage.
7. The implant according to claim 3 wherein said implant comprises
a screw.
8. The implant according to claim 4 wherein said implant comprises
a screw.
9. The implant according to claim 3 wherein said implant comprises
a dental device.
10. The implant according to claim 9 wherein the dental device
comprises a filling of a tooth.
11. The implant according to claim 1 wherein said implant is a long
term implant.
12. The implant according to claim 4 wherein said implant is a long
term implant.
13. The implant according to claim 1 wherein said implant comprises
a radiopaque marker.
14. An implant for a mammal comprising an item comprising BiO.sub.3
and one or more polymers selected from the group consisting of
polyetheretherketone, polyetherketone, polyetherketoneketone,
polyphenylsulfone, and polyetherimide, wherein said implant
comprises BiO.sub.3 in an amount of between about twenty percent
(20%) to thirty percent (30%) by weight.
15. The implant according to claim 14 wherein the mammal comprises
a human.
16. The implant according to claim 14 wherein said polymer
comprises PEEK.
17. The implant according to claim 16 wherein said implant
comprises about thirty percent by (30%) weight BiO.sub.3.
18. A medical device comprising at least ten percent (10%) by
weight bismuth trioxide (BiO.sub.3) and one or more polymers
selected from the group consisting of polyetheretherketone,
polyetherketone, polyetherketoneketone, polyphenlysulfone, and
polyetherimide.
19. The medical device according to claim 18 wherein the device
comprises a stent.
20. The medical device according to claim 18 wherein the device
comprises a catheter.
21. The medical device according to claim 18 wherein the medical
device comprises a screw.
22. The medical device according to claim 18 wherein the medical
device comprises a suture.
23. The medical device according to claim 19 wherein the device
comprises at least about twenty percent (20%) by weight
BiO.sub.3.
24. The medical device according to claim 19 wherein the device
comprises from about twenty percent (20%) to about thirty percent
(30%) by weight BiO.sub.3.
25. The medical device according to claim 20 wherein the catheter
comprises at least about twenty percent (20%) by weight
BiO.sub.3.
26. The medical device according to claim 20 wherein the catheter
comprises from about twenty percent (20%) to about thirty percent
(30%) by weight BiO.sub.3.
27. The medical device according to claim 21 wherein the screw
comprises at least about twenty percent (20%) by weight
BiO.sub.3.
28. The medical device according to claim 21 wherein the screw
comprises from about twenty percent (20%) to about thirty percent
(30%) by weight BiO.sub.3.
29. A medical device comprising polytetrafluoroethylene (PTFE) and
at least ten percent (10%) by weight bismuth trioxide
(BiO.sub.3).
30. The medical device according to claim 29 wherein said device
comprises a portion made by paste extrusion.
31. The medical device according to claim 29 wherein said device
comprises an implant for a mammal.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to certain radiopaque
compositions and articles, and methods of using the same. More
particularly, the invention relates to radiopaque compositions
comprising BiO.sub.3 and articles made therefrom and methods of
using the same in connection with implants, stents, and articles
used in the healthcare and medical fields.
BACKGROUND OF THE INVENTION
[0002] Medical technology has advanced greatly over the years.
Among other things, the use of implants in many areas of the human
body is now conventional. Such implants can be spinal cages and
fillers used for a long term basis within a human body. Such
implants can also be used in connection with dental surgery and
dental applications, such as in fillings in teeth, root canals, and
the like. In addition, the use of various types of fasteners, such
as screws, to hold bones together or to hold foreign objects in
place in or on a human body is conventional. Similarly, the use of
a wide variety of implants, such as catheters or stents, like those
used in vascular and other applications, is conventional. For
example, U.S. Pat. No. 6,517,571, issued to Brauker et al. on Feb.
11, 2003, which is hereby incorporated by reference as if fully set
forth herein, discloses a vascular graft made of
polytetrafluoroethylene paste extrudate that has been expanded.
[0003] In addition to the use of implants, medical technology has
advanced such that the use of various imaging systems during
surgery and other procedures is conventional. For example, the use
of X-ray devices, MRI devices, fluoroscopes, and the like is
conventional for assisting an operator, such as a physician, nurse
or technician, to precisely locate and to identify a tube,
catheter, or other device within a patient's body during the
surgery or other procedure. For example, U.S. Pat. No. 6,463,317,
issued Oct. 8, 2002, to Kucharczyk et al., which is hereby
incorporated by reference as if fully set forth herein, discloses a
device and method for treating an aneurysm during which the device
is inserted into a patient and the device's location in the
patient's body is viewed via X-ray, fluoroscopy, and/or magnetic
resonance imaging techniques.
[0004] There are many situations in which the use of
radiographically opaque (radiopaque) materials is desired.
Radiopaque materials can be easily identified and precisely located
by X-ray examination. In some situations, it is desirable to have a
radiopaque item which is nonetheless optically transparent so that
fluid flow though the device can be viewed.
[0005] In some conventional applications, an entire implant may be
radiopaque. In other situations, however, it may be desirable to
use discrete radiopaque markers of a particular size or shape, or
it may be desirable to use a radiopaque marker in a particular
location of the implant. For example, U.S. Pat. No. 6,340,367,
issued Jan. 22, 2002 to Stinson, et al., which is hereby
incorporated by reference as if fully set forth herein, discloses a
temporary and retrievable radiopaque marker for use on an
implantable endoprosthesis, such as a stent, graft, or stent-graft
(as may be used in coronary angioplasty). Similarly, in Stinson et
al., U.S. Pat. No. 6,626,936, issued on Sep. 30, 2003, which is
hereby incorporated by reference as if fully set forth herein, a
bioabsorbable radiopaque marker for use on an implanted
endoprosthesis such as a stent is disclosed. Still another example
of a radiopaque marker used in an implant is provided by Carter,
U.S. Pat. No. 4,863,470, issued Sep. 5, 1989, which is incorporated
by reference as if fully set forth herein, in which a radiopaque
tab indicating size made from a combination of silicone and either
barium sulfate or bismuth trioxide is included in a breast
implant.
[0006] In connection with medical and healthcare applications, the
use of barium sulfate (BaSO.sub.4) is conventional. Barium sulfate
can be used as a powder to coat various materials that are then
placed in the human body; when an X-ray is taken, the materials so
coated show up clearly in the X-ray. Among other things, barium
sulfate can be added to another material during fabrication such
that the resulting product is radiopaque. For example, barium
sulfate may be added to a polymeric material from which an implant,
such as a spinal cage, is fabricated. The resulting spinal cage is
radiopaque, thus allowing the easy identification and precise
location of the spinal cage when implanted in a body. However, the
density and properties of barium sulfate are such that significant
amounts of barium sulfate are often needed to obtain the desired
amount of radiopacity. Adding significant amounts of barium sulfate
to a polymeric material can result in a weaker structure that does
not have the desired strength.
[0007] The use of various polymers for implants, especially
tubular-shaped implants, is conventional. For example, U.S. Pat.
No. 6,623,823, issued on Sep. 23, 2003, to Onwumere, which is
hereby incorporated by reference as if fully set forth herein,
discloses radiopaque catheters and stents, including a polyurethane
tubing coated with a radiopaque brominated polyurethane coating
composition.
[0008] The use of polyetheretherketone (PEEK) for implants and
medical devices is conventional. PEEK exhibits excellent properties
of strength as well as biocompatibility. PEEK materials, including
implants and PEEK devices for medical applications are available
from a number of commercial sources, such as Invibio, Inc. of
Greenville, S.C. However, PEEK, by itself, is not radiopaque.
Hence, implants and medical devices made from PEEK do not show up
very well in X-ray images. Thus, the precise location and
identification of a PEEK implant from an X-ray can be very
difficult.
[0009] Using devices made from PEEK with barium sulfate
(BaSO.sub.4) has been tried. Although such devices can be
radiopaque due to the addition of barium sulfate to PEEK, the
addition of the necessary amounts of barium sulfate for the desired
radiopacity to the composition tends to weaken the strength of the
resulting device. Thus, the use of an implant made from a
composition of barium sulfate and PEEK provides an undesirable
tradeoff between the desired mechanical properties of the device
and its radiopacity.
SUMMARY OF THE INVENTION
[0010] The present invention solves a number of problems by
providing, among other things, a radiopaque implant made from a
radiopaque composition comprising a polymer such as
polyetheretherketone (PEEK) and bismuth trioxide (BiO.sub.3). In
one embodiment, the implant can be made from a composition
comprising PEEK and bismuth trioxide that can contain up to about
thirty percent (30%) by weight bismuth trioxide. In another
embodiment, a radiopaque implant is provided, which is made from a
composition comprising PEEK and bismuth trioxide that contains an
amount of bismuth trioxide that is in the range of about twenty
percent (20%) to thirty percent (30%) by weight. In still other
embodiments, medical devices such as catheters, stents, screws,
dental fillings, and the like can be made from a composition
containing PEEK and at least about ten percent (10%) bismuth
trioxide. In yet another embodiment of the invention, an
implantable item is provided which has one or more radiopaque
markers. In yet another embodiment of the invention, an implant for
veterinary purposes for implantation into animals (such as but not
limited to mammals other than humans) is provided. In still other
embodiments of the invention, certain other polymers, such as
polyetherketone, polyetherketoneketone, polyphenylsulfone, and
polyetherimide, can be used instead of PEEK.
[0011] It is an object of the invention to provide a radiopaque
implant which is easy to identify and locate via X-ray examination
or fluoroscopy.
[0012] It is another object of the invention to provide a
radiopaque implant which provides the desired amount of radiopacity
while still providing sufficient strength.
[0013] It is another object of the invention to provide a
radiopaque medical device which allows a user to easily identify
and locate the device within a patient's body via X-ray examination
or fluoroscopy.
[0014] These and other objects of the invention will be apparent to
those of skill in the art from the figures and detailed description
which follow.
SUMMARY OF THE DRAWINGS
[0015] FIG. 1 is a radiograph showing an X-ray image of various
tubes, including tubes made in accordance with the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to FIG. 1, a radiograph taken with
conventional X-ray equipment is shown. These X-ray images were
taken at 70 KV for 15 seconds at 15 mA. In FIG. 1, several
different tubes 2, 10, 20, and 30 are shown. Tube 2 is a tube made
of polyetheretherketone (PEEK). Tube 2 has a band 2a in FIG. 1,
with the band 2a the X-ray image of a metal band placed around the
exterior of tube 2. As those skilled in the art will appreciate,
the metal band can be made of any metal that is radiopaque.
[0017] Still referring to FIG. 1, tube 10 is made from a mixture of
PEEK and bismuth trioxide (BiO.sub.3), in which the BiO.sub.3
constitutes about ten percent (10%) by weight of the total
composition from which tube 10 is fabricated. Similarly, tube 15 is
also made from a composition consisting of PEEK and BiO.sub.3, with
the BiO.sub.3 being ten percent (10%) by weight of the composition.
As shown in FIG. 1, tube 15 is slightly larger in diameter than
tube 10. In FIG. 1, tube 20 is made from a mixture of PEEK and
BiO.sub.3 in which the BiO.sub.3 constitutes about twenty percent
(20%) by weight of the total composition from which the tube 20 is
fabricated. In FIG. 3, tube 30 is made from a mixture of PEEK and
BiO.sub.3 in which the BiO.sub.3 constitutes about thirty percent
(30%) by weight of the total composition from which tube 30 is
fabricated. As is shown in FIG. 1, the tube 20 and tube 30 provide
easily identifiable images in the radiograph. A comparison of the
images of tube 20 and tube 30 with the tube 2 having a metal band
shows that the tubes 20, 30 are sufficiently radiopaque for easy
identification and location when tubes 20, 30 are implanted (either
permanently or temporarily, such as during a surgical or other
medical procedure, or when used as a catheter) within a body.
Moreover, the images of tube 20 and tube 30 show sufficient
transparency that the flow of fluids therethrough can be
observed.
[0018] Besides tubing (such as shown in FIG. 1), other articles can
be made in accordance with the invention. For example, the
composition of PEEK and BiO.sub.3, with the amount of BiO.sub.3 by
weight being in the range of from about twenty percent (20%) to
about thirty percent (30%), can be used to fabricate rodstock in
various sizes, as well as square profile rods, and monofilaments in
various shapes and sizes. Such rodstock, square profile, and
monofilament articles can be machined further to obtain desired
shapes and sizes, such as for use as components by subsequent users
of the base shape for such users' own designs or applications. For
example, such monofilaments can be used to form sutures for use to
close wounds or surgical incisions in a patient's body.
[0019] Those skilled in the art will appreciate that the PEEK and
BiO.sub.3 may be obtained from a number of commercial sources. For
example, PEEK may be commercially obtained from Invibio, Inc. of
Greenville, S.C., and BiO.sub.3 may be commercially obtained from
various sources. We have obtained such materials from a compounder,
Fosters Corp., of Putnam Conn. The PEEK may be obtained in
different colors and pellet sizes, and the BiO.sub.3 may be
obtained in a powder form. The BiO.sub.3 powder may be mixed with
the PEEK pellets, and the mixture may then be heated and further
mixed to provide the desired composition containing the mixture of
the BiO.sub.3 in the PEEK. The resulting composition can then be
molded to provide implants of a desired size and shape. Such
implants can include spinal cages, screws, stents, and the like. In
addition, those of skill in the art will appreciate that the
resulting composition can alternatively be extruded, such as in a
conventional manner for PEEK alone. Extrusion may be particularly
useful in forming tubes made of the desired composition, including
catheters, stents, and other implants. In addition, such articles
can be machined to obtain desired shapes and sizes.
[0020] Besides tubing, catheters, grafts, and stents, the
composition comprising PEEK and BiO.sub.3 can be used for a wide
variety of implants for use in the human body. Among other things,
the PEEK and BiO.sub.3 composition as described above can be used
for any of the following types of implants: spinal cages, suture
anchors, spiked washers, surgical screws, femoral implants,
balloons, intracardiac pumps, heart valves, finger joints, hip and
femoral bone replacements, bone screws and pins, dental posts and
caps, and so forth.
[0021] PEEK provides a number of advantages. PEEK is biocompatible
and biostable. PEEK articles may be easily sterilized, a
conventional requirement for articles to be used in vivo with human
patients. PEEK has inherent lubricity. PEEK is extremely
strong--carbon fibers can be added to PEEK in order to obtain an
article with mechanical properties of strength substantially the
same as those of healthy human bones. PEEK typically has a melting
point of about 343.degree. C., a crystallization peak of about
160.degree. C., and a glass transition temperature of about
145.degree. C. PEEK can be extruded and injection molded by
conventional techniques.
[0022] Those skilled in the art will also understand and appreciate
that, depending on the particular application involved, other
alternative polymers may be used in place of PEEK. Those skilled in
the art will appreciate that in place of PEEK, other
polyaryletherketones may be used as the polymer component of the
composition. For example, the polymer commercially available under
the trademark PARMAX, which is commercially available from Solvay
Advanced Polymers of Alpharetta, Ga., has appropriate mechanical
and chemical properties such that it can be mixed with BiO.sub.3 to
obtain a radiopaque implant with the desired characteristics.
PARMAX is a self-reinforcing polymer that is an amorphous,
melt-processable engineering thermoplastic. Other appropriate
polymers include polyetherketone, polyetherketoneketone,
polyphenylsufone, polyetherimide, and the polymers commercially
available under trademarks RADEL.RTM., which is also commercially
available from Solvay Advanced Polymers, and ULTEM
(polyetherimide), which is commercially available from the General
Electric Company of Schenectady, N.Y.
[0023] Those skilled in the art will also appreciate that other
polymers may be used in accordance with the invention. Such other
polymers may include liquid crystal polymers, polyphthalamides, and
polyarylamides. These latter polymers are either self-reinforcing
polymers or can be reinforced with glass or carbon fibers. Each of
these latter polymers are biocompatible in connection with short
term blood contact.
[0024] In addition to the above polymers, the invention in another
embodiment involves the use of a composition of
polytetrafluoroethylene (PTFE) and BiO.sub.3. The composition can
be prepared such as described above, such as with BiO.sub.3 in the
amount by weight of from about twenty percent (20%) to about thirty
percent (30%), by mixing PTFE and BiO.sub.3 in powder form. The
mixture can then be fabricated using conventional paste extrusion
techniques and equipment. For example, the mixture of PTFE and
BiO.sub.3 can be combined with a liquid to disperse the PTFE and
BiO.sub.3 powder mixture, the dispersion blend may be extruded, and
then the liquid may be removed, such as by drying or sintering.
Those skilled in the art will appreciate that the PTFE and
BiO.sub.3 need not be mixed together in powder form first, but can
be added to the liquid one after another.
[0025] Those skilled in the art will appreciate that implants made
in accordance with the present invention may be either short term
or long term implants. Indeed, articles made in accordance with the
invention need not be implanted, but may be inserted into a
patient's body for use during surgery or other medical procedures,
then removed from the patient's body when the surgery or other
procedure is finished. (Although regulations of the U.S. Food &
Drug Administration (F.D.A.) define an "implant" as a "device that
is placed into a surgically or naturally formed cavity of the human
body if it is intended to remain there for a period of 30 days or
more," those skilled in the art will appreciate that "implant" as
used herein is also intended to include even those articles
temporarily placed into a human body, as well as in any other
animal body, including those of mammals other than humans.)
"Implant" as used herein is intended to include any device which is
inserted wholly or partially into a subject's body cavity (whether
the subject is human or not), including those types of devices
deemed an implant pursuant to F.D.A. regulations, such as those
found in 21 C.F.R., Parts 870, 872, 874, 876, 878, 880, 882, 886,
and 888 (as of April 2005). Those skilled in the art will also
understand and appreciate that, although most of the foregoing
discussion involves human patients, the articles and implants made
in accordance with the invention may be useful in other areas as
well, including in veterinary situations in which the patient is a
cow, dog, cat, horse, or other mammal and not a human patient.
[0026] Radiopaque articles made in accordance with the present
invention may be used in a variety of situations. As noted, such
articles may be used as implants in a variety of applications. Such
implants may be either short term implants or long term implants.
In addition to use as implants, however, articles made in
accordance with the invention may be used during surgical and other
medical procedures. For example, a catheter (not shown) may be
provided that has been made from a composition of PEEK and
BiO.sub.3, with about thirty percent (30%) by weight of the
composition consisting of BiO.sub.3. The catheter may be formed as
a tube of a desired inner diameter size and outer diameter size. In
addition, the catheter so formed may be of a desired length. Such a
catheter in accordance with the invention may be used by inserting
it into a patient's body, such as into an incision made to allow
drainage from within the body. In addition, such a catheter may be
inserted into a blood vessel and then guided by an operator (such
as a physician) to a desired location, such as a blocked blood
vessel in connection with coronary angioplasty. During the
procedure, the operator can view a fluoroscope of a conventional
type in order to identify and precisely locate the catheter as it
is guided to the desired location in the patient's body. Once the
operation is completed, the operator can then remove the catheter
from the patient's body. Besides applications in coronary surgery,
such a catheter may be used in any type of surgery in which the
precise location of a catheter is desired, such as in neurological,
ophthalmic, cosmetic, and dental surgeries, among others. In such
situations, the use of a radiopaque article made in accordance with
the present invention will be advantageous, as doing so allows the
operator to determine the precise location of the article within
the patient's body via the use of conventional X-ray, fluoroscopy,
and/or magnetic resonance equipment. In addition, articles made in
accordance with the present invention also are advantageous in that
they may be fabricated to varying degrees of radiopacity. Referring
back to FIG. 1, it can be seen that tube 30 (which was made from a
composition consisting of thirty percent (30%) by weight BiO.sub.3
and the remainder PEEK) is not totally radiopaque, but is
sufficiently so to allow easy identification and location via an
X-ray examination. At the same time, however, the tube 30 is
sufficiently radiolucent that an operator may be able to view the
movement of fluids or other items through tube 30 via X-ray
examination or fluoroscopy with conventional equipment. As also
shown in FIG. 2, tube 2 (which is made from a composition of twenty
percent (20%) by weight BiO.sub.3 and the remainder PEEK) is less
radiopaque than tube 30. Those skilled in the art will appreciate
that the desired degree of radiopacity (or conversely,
radiolucence) may be obtained by varying the relative amounts of
BiO.sub.3 and PEEK in the composition from which a desired article
is to be made.
[0027] Those skilled in the art will appreciate that the foregoing
description of the invention is of a preferred embodiment and of
certain specific alternative embodiments, and that various changes,
modifications and other variations and adaptations thereof may be
made without departing from the scope and spirit of the invention
as set forth in the claims. The specific embodiments, and the
dimensions, materials, and the like are merely illustrative and are
not intended to limit the scope of the invention, as set forth in
the claims.
* * * * *